Composite metal.



UNITED sTA s PATENT OFFICE.

COMPOSITE METAL.

Specification of Letters Patent.

Patented April 16, 1907.

Original application filed March 30, 1905, Serial No. 252 ,93 8i Divided and this application filed January 20,1906. Serial No. 296,95 5.

To all whom it may concern:

Be it known that I, THOMAS ALVA. EDISON,

a citizen of the United States, residing at Llewellyn Park, Orange, in the county of Essex and State of New Jersey, have invented a certain Composite Metal, of which the following is a description. I t In an application for Letters Patent filed March 30, 1905, Serial No. 252,933, I have described an improved process for making a composite metal, and I propose herein to describe and claim the new product so secured. The new composite metal consists of two or more metals physically admixed in such a Way that each metal exists as a practically integral sponge-like structure, the cells or pores of either metal being completely tilled by the body presented-by the other metal, whereby the entire bulk of the composite structure as a whole will be continuously solid throughout. Such a composite metal is characteristically distinguished from any so-called alloy heretofore made, so far as I know, in the respect that it consists of sponge-like interlocking masses, so that it becomes possible by dissolving or otherwise removing one of the metals to obtain a sponge-like integral mass of the other metal, whereas with ordinary alloys, owing to their intin'iatc molecular :uimixture, the attempt to dissolve an one of the mmstituents of the the alloy results in the disintegration of the mass. This clmracteristic peculiarity of my improved composite metal makes it-possiblc to secure very beautiful spou inr-like effects in various metals by first forming the composite metal and then removing one bl' the metals, and it also becomes possible to secure attractive effects in many arts where it .is desirablc that two or more metals should be mechanically associated together.

The primary purpose for which I have used the composite metal referred to is for the rn'miuction of scales, llakes, or foils of nickel and cobalt for admixture with the active material in the negative electrode of my improved storage battery. As I have pointed out in application for Letters Patent liled March 30, 1905, Serial No. 252,035, good contact with such active material and between the ilakes or foils themselves is secured when metallic cobalt is used; but, asl have explained, it is mulesirable to use. metallic in prevents penetration .of oxidation Within the nickel-cobalt to a harmful extent, since the metallic nickel forms a continuous inte gral connecting-sponge, and therefore protects the cobalt from the possibility of inward oxidation. to any harmful extent.

Assuming a composite metal of nickel and cobalt to be manufactured for the purpose offorming scales, films, or foils for use in the make-up of my improved battery, I proceed substantially as follows: A solution of sulfate of nickel and sulfate of cobalt is first obtained in the proper relative quantity to give to the resulting product the desired proportions of the two metals. Excellent results have been secured with a composite metal containing sixty per cent. of cobalt and forty per cent. of nickel; but these proportions may be varied within quite wide limits. The solution of cobalt. and nickel sulfates is now added to a potash solution in excess of that necessary to precipitate the two salts, and the two solutions thus added are boiled, .resulliii'ig in the precipitation of hydroxids of nickel and cobalt, which are allowed to settle. The solution is now drawn oil and the n*ecipilaled mixed hydroxids are washed successively until the mass is free of potash and sulfates. In this way I obtain a physically and intimately mixed mass of hydroxids of the two metals in the desired proportion. The mixed h' \'droxids are now dried and screened into granules of substantially uniform size-loiinstance, those passing a thirt' -mesh screen and arrested by a sixtymesh screen--after whichthe granules are subjected to the reducing action by hydrogen gas in a heated retort to reduce the hydroxids to the respective metals and also to weld together the metallic particles constituting each of the granules, so that each granule will be composed of a combinatioiii of the two metals having the characteristics before pointed out. The reduced metallic granules are now subjected to successive rolling operations with oil to convert the composite metal into fine scales or flahes -as is common in the art, for example, ol making bronze powder. Preferably the flakes are annealed two or more times between the passes oi the r'olllng operation in an inert gas, sueh as hydrogen, at a real heat. After the (lakes or foils are formed it is r increase their bulk to pass them between Very fine erin'1ping-rolls, by which they wil be erimped, eorrugatei i, or otherwise (listorted or between rolls of very si nall diameter, by which they will be curlel} or termed into minute spirals.

in any suitable way, prelembly by coating the active particles with a stick material, such as molasses, ktliil then aanuxing the same with the metallic flakes or scales, as l have (lGSCIllNHl in an application for Letters Patent lllOil March 30, 1905, Serial No,

lesirable in 01110! to These flakes or toils are added to the active material of the l'mttery llaving new described my invention, what E I claim as new, and desire to secure by Lett'ers Patent, is as iollows:

l. A composite eoi'nposed oi two or more metals, each in the form of a substantially integral sponge-like structure and saitl structures being engaged intin'iately together to constitute a solid mass, substantially as and 1' for the purposes set forth.

2. A composite composed of cobalt and niekel, each in the form of a substantially integral sponge-like structure intimately engaging together to form a eontinuous solid mass, substantially as and im the purposes set 1orth. V

This speciliea't ion signed and witnessed this 19th (lay oifllnnuary, 1906. i

Witnesses:

Fniwir ll. Urnn, i Axx'a lt. Kenn. 

